Abstract Detail

Patterns and Processes of American Amphitropical Plant Disjunctions: New Insights

Villaverde, Tamara [1], Escudero, Marcial [2], Bruederle, Leo P. [3], Starr, Julian R. [4], Martí­n-Bravo, Santiago [1], Luceño, Modesto [1].

The bipolar disjunction in biogeography: case studies in genus Carex (Cyperaceae).

One of the most fascinating plant distribution patterns is the bipolar disjunction. Bipolar species occur at very high latitudes (>55°N and >52°S) in both hemispheres, regardless of their distribution in intermediate areas. Thirty vascular plant species have such distribution, being Carex (Cyperaceae) the genus with the largest number of bipolar species (C. arctogena, C. maritima, C. canescens, C. magellanica, C. macloviana and C. microglochin). It is also the best-studied genus in this respect, since different biogeographic hypotheses (vicariance, convergent evolution, long-distance dispersal and human introduction) have been tested for the six species. We review the biogeographic studies of the six bipolar Carex species based on morphological, molecular and bioclimatic data. The low levels of genetic differentiation found between populations of both hemispheres for all six species and relatively recent times of diversification allow us to reject all but the long-distance dispersal hypothesis (including direct long distance dispersal and mountain hopping). The species probably migrated from the Northern Hemisphere to the Southern Hemisphere, occupying different climatic niches in each hemisphere.

1 - Universidad Pablo de Olavide, Molecular Biology and Biochemical Engineering, Botany Area, Ctra. de Utrera, Km1 sn, Seville, Seville, 41013, Spain
2 - Universidad de Sevilla, Plant Biology and Ecology, Botany Area, C/ S. Fernando, 4, Seville, Seville, 41004, Spain
3 - University of Colorado Denver, Integrative Biology, Campus Box 171, Denver, CO, 80217-3364, USA
4 - University of Ottawa, Department of Biology, Ottawa, ON, K1N 6N5, Canda

Keywords:
bipolar disjunction
Carex
climatic niche
Biogeography
Cyperaceae
divergence time estimation
long-distance dispersal.

Presentation Type: Colloquium Presentations
Session: C2, Patterns and Processes of American Amphitropical Plant Disjunctions: New Insights
Location: 204/Savannah International Trade and Convention Center
Date: Tuesday, August 2nd, 2016
Time: 3:00 PM
Number: C2007
Abstract ID:145
Candidate for Awards:None